Pelvic Response Investigation of Lateral Loading Conditions using Finite Element Models

Since the limited space between the car structure and an occupant makes it difficult to manage side impact energy, much biomechanical investigation has been done by subjecting the pelvis to lateral loading. In this study, the dummy finite element model was partially modified to verify the lateral pelvic loading by a rectangular shape impactor and used to explain in detail the previous investigation under iso-energy. In order to better understand the influence of impact mass and velocity under iso-energy, linear momentum and total energy conservation theories were introduced. Using driven equations from the theories and the simplified pelvis model, this study proved that the maximum internal energy levels should be different under iso-energy: the greater the impact mass, the less the internal energy level. This finding correlates with the previous pelvis loading investigation: the greater the impact mass, the less the pelvic loading, since it was shown that the impact loading is proportional to the internal energy. Thus, this study calculated the impact mass and velocity combinations to maintain the same internal energy level based on analytical solutions and finite element simulations. Closed values of the maximum pelvic forces were obtained when the calculated impact mass and velocity conditions were applied on the dummy lateral impact model. Furthermore, this methodology in conjunction with the analytical solution and the finite element simulation should be an appropriate way to set up the impact test configurations using manageable internal energy levels which may help to better understand the loading characteristics.